scholarly journals Optimal control strategies of eradicating invisible glioblastoma cells after conventional surgery

2015 ◽  
Vol 12 (106) ◽  
pp. 20141392 ◽  
Author(s):  
Aurelio A. de los Reyes V ◽  
Eunok Jung ◽  
Yangjin Kim
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Cell Fate ◽  
Control Strategies ◽  
Metabolic Stress ◽  
Point Of View ◽  
Drug Infusion ◽  
Conventional Surgery ◽  
Cell Growth And Migration ◽  
Signalling Molecules

Glioblastoma, the most aggressive type of brain cancer, has median survival time of 1 year after diagnosis. It is characterized by alternating modes of rapid proliferation and aggressive invasion in response to metabolic stress in the microenvironment. A particular microRNA, miR-451, and its downstream signalling molecules, AMPK complex, are known to be key determinants in switching cell fate. These components form a core control system determining a balance between cell growth and migration which is regulated by fluctuating glucose levels in the microenvironment. An important factor from the treatment point of view is that low levels of glucose affect metabolism and activate cell migration through the miR-451-AMPK control system, creating ‘invisible’ migratory cells and making them inaccessible by conventional surgery. In this work, we apply optimal control theory to deal with the problem of maintaining upregulated miR-451 levels that prevent cell infiltration to surrounding brain tissue and thus induce localization of these cancer cells at the surgical site. The model also considers the effect of a drug that blocks inhibitive pathways of miR-451 from AMPK complex. Glucose infusion control and drug infusion control are chosen to represent dose rates of glucose and drug intravenous administrations, respectively. The characteristics of optimal control lead us to investigate the structure of optimal intravenous infusion regimen under various circumstances and predict best clinical outcomes with minimum expense possible.

scholarly journals An Underactuated Drift-Free Left Invariant Control System on a Specific Lie Group

2012 ◽  
Vol 2012 ◽  
pp. 1-14
Author(s):  
Camelia Pop Arieşanu
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Lie Group ◽  
Point Of View ◽  
Free Left ◽  
Invariant Control

The paper presents a geometrical overview on an optimal control problem on a special Lie group. The Hamilton-Poisson realization of the dynamics offers us the possibility to study the system from mechanical geometry point of view.

scholarly journals Energy Near-Optimal Control Strategies for Industrial and Traction Drives with a.c. Motors

2017 ◽  
Vol 2017 ◽  
pp. 1-22 ◽  
Author(s):  
Ján Vittek ◽  
Peter Butko ◽  
Branislav Ftorek ◽  
Pavol Makyš ◽  
Lukáš Gorel
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Energy Savings ◽  
Position Control ◽  
Control Strategies ◽  
Time Profile ◽  
Optimal Controls ◽  
Zero Dynamic ◽  
Loop Dynamics ◽  
Traction Drives

The main contribution of this paper is a new rest-to-rest position control system for use with electric drives employing a.c. motors that is near-optimal with respect to combined electrical and frictional energy waste minimization. The friction has constant, linear, and quadratic components with respect to the rotor speed. The closeness to optimality is assessed by simulation, comparing the energy loss of the new control system with that predicted by computed optimal controls. The application of the near-optimal control system is rendered straightforward by using a symmetrical trapezoidal speed-time profile. This is provided by an energy saving reference position generator whose output is faithfully followed by means of a feedback control law based on forced dynamics control yielding prescribed closed loop dynamics, together with a matched zero dynamic lag precompensator. For load torque consisting of constant, linear, and quadratic components also maneuver time is optimized if it can be chosen arbitrary. Two case studies, one applied to position control of rotational drive and second one applied to train movement, confirm the possibilities of achieving energy savings.

scholarly journals WIRELESS-BASED TECHNOLOGY FOR OPTIMIZING OF OPERATION OF THE AVIATION ENGINE CONTROL SYSTEM

Aviation ◽  
2021 ◽  
Vol 25 (1) ◽  
pp. 35-40
Author(s):  
Serhii Tovkach
Keyword(s):  
Control System ◽  
Information Exchange ◽  
Control Strategies ◽  
Optimization Method ◽  
Point Of View ◽  
Theoretical Point ◽  
Common Error ◽  
Adaptive Wavelet ◽  
High Productivity ◽  
Engine Control System

An approach for improving of efficiency the operation of distributed control system of aviation engine based on wireless technology with high productivity and resolution of wave distributed surface has been presented. It can be applied for development of new principles of correct location the nodes, including the data processing equipment, the intellectual sensors, actuators, repeaters, central units in adaptive control strategies of aviation engine. The optimization method for processing information, using adaptive wavelet filters, as an optimal filter, that minimizes the average square of a common error for organizing the connection between wireless elements in the control systems of aviation gas turbine engine, has been considered, on the theoretical point of view. Also, the wavelets applications in the Wireless Distributed Automatic Control System (WDACS) for aviation engine, the requirements for the construction of its node, supported by the protocol stack, the scheme and the programs with a combination of connections the information exchange between elements have been considered, from the practical point of view.

scholarly journals Control system studies of an active anti-roll bar tilt system for railway vehicles

1998 ◽  
Vol 212 (1) ◽  
pp. 43-60 ◽  
Author(s):  
J. T. Pearson ◽  
R. M. Goodall ◽  
I Pratt
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Control Systems ◽  
Control Strategies ◽  
Railway Vehicle ◽  
Control Approach ◽  
Advantages And Disadvantages ◽  
System Requirements ◽  
Optimal Control Approach ◽  
Modelling Process

This paper describes a theoretical study of an active anti-roll bar tilt control system for a railway vehicle. It presents the rationale behind body tilting, the advantages and disadvantages associated with body tilting and the key tilt control system requirements. The paper also describes the control modelling process and presents some simulation results from control system studies. A number of competing control systems have been designed and analysed, including both classical and optimal control strategies. The performance of the control systems for a variety of curves is considered, as well as their response to track irregularities. The results show that all the strategies provide good tilting performance, the optimal control approach being marginally better.

scholarly journals On the reproduction number and the optimal control of infectious diseases in a heterogenous population

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
A. U. Chukwu ◽  
J. A. Akinyemi ◽  
M. O. Adeniyi ◽  
S. O. Salawu
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Infectious Diseases ◽  
Matrix Method ◽  
Ebola Virus ◽  
Reproduction Number ◽  
Control Strategies ◽  
Susceptible Population ◽  
Heterogenous Population ◽  
Next Generation Matrix

Abstract The effect of infectious diseases cannot be overemphasised. The continuing surfacing of the infectious diseases gives the stakeholders a great concern. In this paper, the nature of the spread of Ebola virus outbreak in West Africa in 2014 is studied. We develop a model that analyses the spread of infectious diseases, and the reproduction number is determined by using the next generation matrix method. Finally, the effects of treatment of the infected individuals and vaccination of the susceptible population as the control strategies are looked into. The optimal control system showed that the combination of the two strategies proved more effective.

Temperature Control System for Transformer Three-Phase 50 Hz 2500 kVA

2017 ◽  
Vol 3 (2) ◽  
pp. 88
Author(s):  
Suci Rahmatia ◽  
Marsah Zaysi Makhudzia
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Heat Loss ◽  
Temperature Control ◽  
Electrical Energy ◽  
Temperature Control System ◽  
Iron Core ◽  
Electrical Device ◽  
Optimal Control System ◽  
Three Phase

<p><em>Abstrak <strong>- </strong></em><strong>Transformator adalah peralatan listrik yang sangat vital dalam proses pembangkitan maupun transmisi energi listrik karena transformator dapat menaikkan atau menurunkan tegangan. Pada proses menaikkan dan menurunkan tegangan biasanya sering timbul panas akibat rugi – rugi tembaga pada inti besi dan kumparannya sehingga pada kondisi overload akan menimbulkan pemanasan yang berlebih dan dapat mempengaruhi kinerja transformator. Oleh karena itu dibuat sistem kontrol temperatur pada transformer yang dapat mengontrol temperatur di dalam transformator saat bekerja pada kondisi overload, sehigga transformatornya tidak terbakar. Dial thermometer digunakan sebagai alat yang mengontrol temperatur transformator pada sistem kontrol temperatur. Agar mendapatkan sistem kontrol yang optimal, maka setting temperatur pada dial thermometer di sesuaikan dengan temperatur maksimal tranformator dapat bekerja. Sehingga pada saat temperatur tertentu dial thermometer dapat memberikan sinyal untuk membunyikan alarm dan mengaktifkan kontrol kipas sehingga kipas dapat bekerja menurunkan temperatur transformator.<em></em></strong></p><p><strong><em> </em></strong></p><p><strong><em>Kata kunci - </em></strong><em>transformator, rugi – rugi tembaga, temperatur, sistem kontrol, dial thermometer<strong>.</strong></em></p><p><strong><em> </em></strong></p><p><em>Abstract <strong>- </strong></em><strong>A transformer is an electrical device that is vital in the generation and transmission of electrical energy because the transformer can raise (stepping up) or lower (stepping down) the voltage. In the process of raising and lowering the voltage is usually often caused heat loss of copper in iron core and coil so that the overload condition will cause excessive warming and can affect the performance of the transformer. Therefore, a temperature control system on the transformer can control the temperature inside the transformer while working under overload conditions, so the transformer is not burned. Dial thermometer is used as a device that controls the temperature of the transformer in the temperature control system. In order to obtain an optimal control system, the temperature setting on the dial thermometer adjusted to the maximum transformer temperature can work. So that when a certain temperature dial thermometer can provide a signal to sound the alarm and activate the fan control so that the fan can work down the transformer temperature.</strong></p><p><strong> </strong></p><p><strong><em>Keywords -  </em></strong><em>transformator, loss of copper, themperature, control system, dial thermometer<strong></strong></em></p>

scholarly journals Impedance Matching-Based Power Flow Analysis for UPQC in Three-Phase Four-Wire Systems

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2702
Author(s):  
Xiaojun Zhao ◽  
Xiuhui Chai ◽  
Xiaoqiang Guo ◽  
Ahmad Waseem ◽  
Xiaohuan Wang ◽  
...  
Keyword(s):  
Power Flow ◽  
Control Strategies ◽  
Impedance Matching ◽  
Flow Analysis ◽  
Point Of View ◽  
Impedance Model ◽  
Power Flow Analysis ◽  
Three Phase ◽  
System Node ◽  
Power Quality Conditioner

Different from the extant power flow analysis methods, this paper discusses the power flows for the unified power quality conditioner (UPQC) in three-phase four-wire systems from the point of view of impedance matching. To this end, combined with the designed control strategies, the establishing method of the UPQC impedance model is presented, and on this basis, the UPQC system can be equivalent to an adjustable impedance model. After that, a concept of impedance matching is introduced into this impedance model to study the operation principle for the UPQC system, i.e., how the system changes its operation states and power flow under the grid voltage variations through discussing the matching relationships among node impedances. In this way, the nodes of the series and parallel converter are matched into two sets of impedances in opposite directions, which mean that one converter operates in rectifier state to draw the energy and the other one operates in inverter state to transmit the energy. Consequently, no matter what grid voltages change, the system node impedances are dynamically matched to ensure that output equivalent impedances are always equal to load impedances, so as to realize impedance and power balances of the UPQC system. Finally, the correctness of the impedance matching-based power flow analysis is validated by the experimental results.

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